The present invention relates to the technical field of locating a firearm in three dimensions on the basis of acoustic detection, where the term "firearm" is used broadly, e.g. to cover an individual weapon such as a shot gun or a rifle, or a weapon requiring a crew such as a machine gun, a mortar, or a field gun.
More precisely, the invention covers the field of using acoustic detection to locate firearms that fire projectiles having a muzzle velocity that is preferably, although not exclusively, supersonic.
An ever-increasing need can be seen, particularly due to attacks by guerillas, armed civil conflicts, or in the context of humanitarian action taken in unstable regions, to have technical means for locating firearms liable to cause damage, whether to people or to property. It has been found that marksmen, even though often isolated, are nevertheless capable of constituting a real danger against which it is difficult to provide effective protection.
Systems, and in particular acoustic systems have therefore been developed to warn people that they are being shot at. For example, an acoustic detection system is known for helicopters so as to warn the crew that the helicopter is under fire, it being understood that the crew members cannot hear the sound of firing because of the high level of noise that exists in the helicopter.
Nevertheless, that system constitutes no more than means of providing a warning that shots are being fired, and it is incapable of indicating the position of the weapon, such that the people under fire cannot determine their best position for sheltering from the fire or for taking out the aggressor.
There is therefore a need to have means that are suitable for accurately locating a firearm, in order to enable appropriate measures to be adopted for protecting people or property.